（8X-9)²+2/9y-8/=0
8x-9=0 x=9/8
9y-8=0 y=8/9
xy=1
2xy-x/3x-2y+xy-2/2y-3x+x-3/3x-2y
=(1-x)/(3x-2y)+(2-1)/(3x-2y)+(x-3)/(3x-2y)
=(1-x+1+x-3)/(3x-2y)
=-1/(3x9/8-2x8/9)
=-1/(27/8-16/9)
=-1/(115/72)
=-72/115